RE: ZFS snapshots

From: Kevin Closson <kevinc_at_polyserve.com>
Date: Tue, 12 Dec 2006 09:30:53 -0800
Message-ID: <5D2570CAFC98974F9B6A759D1C74BAD001C3378F@ex2.ms.polyserve.com>

I can only talk about filesystem snapshots that I know. With veritas and the upcoming
polyserve snapshots, if all files are in one directory, a snapshot looks EXACTLY like a
database that was running on a system where the power was turned on. Exactly.  

---

        From: oracle-l-bounce_at_freelists.org
[mailto:oracle-l-bounce_at_freelists.org] On Behalf Of Donahue, Adam

	Sent: Tuesday, December 12, 2006 6:59 AM
	To: Kerber, Andrew; oracle-l_at_freelists.org
	Subject: RE: ZFS snapshots
	
	
	Well, a ZFS snapshot is atomic - meaning, it's not like copying

a datafile in that it doesn't read things block-by-block, meaning the file can change underneath you while you copy it. Instead, because of the way ZFS works, it merely marks an existing "uberblock" to be preserved, which is a single, atomic state of the filesystem as of a given time.          

        I admit it's not clean - even if it works. But I'm curious if I'm missing something that would make it not work at all in some cases.          

        is not indicative of future returns.

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Received on Tue Dec 12 2006 - 11:30:53 CST